Question: When did Durham had a population of 6679 people?
Paraphrase: At what time did Durham have 6679 people living there?
SPARQL (Wikidata): SELECT ?value WHERE { wd:Q49229 p:P1082 ?s . ?s ps:P1082 ?x filter(contains(?x , '6679.0')) . ?s pq:P585 ?value}